Quaternary ammonium biocides (disinfectants) are well known and widely used. Unfortunately such materials suffer from a number of deficiencies resulting from their "cationic" nature. In particular, because they are highly susceptible to precipitation by a wide of variety of materials, such precipitation leads to removal and deactivation of the quaternary ammonium compound in a biocidal sense.
More particularly, quaternary ammonium biocides are precipitated from aqueous media and thus lose their effectiveness and are rendered inactive by a variety of organic "soils." Some of the soils are natural to the environment in which the disinfectant cleaner is to be used (blood serum, animal waste, fats, etc.). Some of the "soils" are in fact other ionic species, such as anionic surfactants, electrolytes, polyvalent ions, and similar materials. When deactivation occurs, the biocidal activity of the quaternary ammonium compound is dramatically diminished, even with organisms that the quaternary ammonium compound normally controls very readily such as gram positive bacteria.
This lack of activity in the case of quaternary ammonium biocides is well known and well documented with respect to particular pathological organisms, e.g., Mycobacterium tuberculosis, Hepatitis B virus, Polio Myelitis virus, and Canine Parvo virus. In order to compensate for these deficiencies, certain other "non-quaternary" biocides such as phenolic biocides, halogen-based biocides, etc., have been proposed for use with quaternary ammonium biocides.
Another deficiency of quaternary ammonium compounds is that their wetting and degreasing properties are less than desired. For example, cleaning products formulated with quaternary ammonium compounds often are not particularly effective when used on surfaces that are either porous or coated with an oily layer, or both. Indeed, among all surfactants, quaternary ammonium compounds are the poorest wetting agents. Also, they are generally poor emulsifiers. Moreover, due to adverse interaction with other surface actives, formulation of quaternary ammonium compounds is often impracticable.
Wetting is a very important attribute for any liquid products, especially when liquid formulations (e.g., products designed to kill germs on hard surfaces) need to penetrate into fine cracks or pores where shear force can not be adequately applied. Because of precipitation in the presence of conventional anionic surfactants, the options for surface tension reduction or better wetting properties are very limited. Although nonionic surfactants such as alcohol ethoxylates and ethoxylated alkylphenols can be used to enhance the wettability of quat-based liquid formulations, unfortunately the presence of nonionics adversely affect the germicidal efficiency of the quaternary ammonium compounds.
The cationic charge on quaternary ammonium compounds is responsible for their germicidal function. Unfortunately, however, undesirable deposit formation and buildup on hard surfaces is also attributable to the cationic charge of quaternary ammonium compounds. In particular, the positive charge tends to cause the quaternary ammonium compound to orient itself on the hard surface during application. As the carrying solvent evaporates, a hydrophobic surface can form, and this in turn can attract deposition thereon of greasy substances.
It would thus be of considerable advantage if a way could be found of improving the surfactant properties of quaternary ammonium compounds while at the same time not jeopardizing or impairing their germicidal properties. This invention is deemed to make possible the achievement of these objectives.